


Secret Santa: Most precious gift

by aellisif



Series: Secret Santa Series [2]
Category: Transformers: Prime
Genre: Oral Sex, Other, Sex Toys, Sticky Sexual Interfacing
Language: English
Status: Completed
Published: 2020-07-16
Updated: 2020-07-16
Packaged: 2021-03-04 17:28:36
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,116
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25320121
Author URL: https://archiveofourown.org/users/aellisif/pseuds/aellisif
Summary: On the eve of their bonding ceremony, Optimus revisits his old stargazing spot near Jasper just to get away from the bustle of the preparations.Megatron has a last-minute question. Optimus finds out that he does, too.
Relationships: Megatron/Optimus Prime
Series: Secret Santa Series [2]
Series URL: https://archiveofourown.org/series/1833973
Comments: 14
Kudos: 110





	Secret Santa: Most precious gift

**Author's Note:**

> Because I wanted to know what happened after Secret Santa, gladiator-style, and well, this was the result.
> 
> Un-betaed, please let me know if you find any errors.

“I really should have figured out you would come here.”

Optimus continued looking at the stars, but he did chuckle. “Did Soundwave or Jazz point you in the right direction?” he asked and Megatron huffed, looming over him where he lay on his blanket.

“Given that your intelligence officer doesn’t seem to think anything of disclosing your location, I have to seriously wonder why we never managed to find you alone.”

Optimus chuckled again and turned his helm to meet the red optics. “I would hope Jazz need have no worries disclosing my location to my soon-to-be conjunx.”

Megatron made an indefinite sound and continued staring at him. Optimus raised an optic ridge. “Is there anything that requires my attention back on Cybertron? I thought all of the preparations were finished.”

“I was looking for you,” Megatron said, sounding unusually hesitant, and Optimus pushed himself up on his elbows, tank fluttering. Coming to Earth to do some stargazing had been a spur-of-the-moment decision, trying to escape the flurry at the joint headquarters of the Decepticon-Autobot command. Not that Optimus did not understand all the anticipation and nerves; after all, he was going to conjunx Megatron only a few groons hence. But if he wanted to maintain some sort of equilibrium, he had needed to get out of the bustle. Earth had seemed like the best solution, so he had taken a spacebridge to his old favourite stargazing spot.

Of course, he could not come here without the blanket Megatron had hidden for him to find close to said spot, and he had indeed found that spreading it out on the ground and huddling inside had returned some peace of processor to him, just like the first time he had lain there, even without the help of high-grade.

Megatron’s arrival in person, though, that was rather unexpected and immediately raised warning flags in his processor.

“What is the matter?”

Megatron cleared his intake and, inexplicably, looked away. “Soundwave suggested that, seeing as our bonding ceremony is in a few groons, you and I take the opportunity to – determine our compatibility. I could not find you in your quarters, so I went looking and followed you here.”

Optimus reset his optics and Megatron lit up on his infrared sensors, then made a fairly rude, but unmistakable gesture, and Optimus lit up as well as he caught on to which kind of compatibility Soundwave had been talking about. “Oh.”

Silence.

“Yes,” Megatron said gruffly and sat down beside Optimus, still not looking at him. He cleared his own intake.

“Ratchet has … mentioned something along the same lines lately.”

Kindly put. What Ratchet had _really_ said was not something Optimus would ever repeat to Megatron without threat of immediate deactivation.

“We – have been taking our time,” he said, half question, half statement, and saw Megatron nod jerkily. They had been taking their sweet time with interfacing, that was certainly true, born of a combination of awkwardness around each other now that their intentions and feelings were out in the open, and lingering wariness from their more than rocky history. Optimus didn’t think that had been a bad decision to make, per se; taking their time to get to know each other again, after so many millennia apart, finding political compromises and a middle ground without the possibility to drag their conflicts into berth had certainly made things easier. In fact, waiting with interfacing had been one of their first joint decisions after they had ended up flat on the conference table after one particular meeting and realised that neither of them quite dared open their interface panel and bare themselves to the other, not while their battle protocols were warring for attention with the interface protocols.

Unreleased tensions this way or that, they had waited for so long, neither of them was willing to taint their first time with lingering distrust and suspicion, so Megatron had slowly pushed himself up from where he was pinning Optimus to the table and rasped, “Maybe we should fuel together?”

Disappointed and relieved in equal measure, Optimus had agreed and gotten up, and then they had gone to fuel together in the officers’ mess and carefully, hesitantly, broached the topic of interfacing with each other. It had required a certain amount of control, of course, but if they were anything, it was stubborn, so they stuck to their guns, so to speak, and relieved their tension by themselves. At least, Optimus had; it was none of his business whether Megatron berthed one of his subordinates to take care of the lingering charge, although he suspected that he either didn’t, or went to Soundwave. Because there was no gossip about Megatron’s berth partners, whereas there was plenty of gossip (and betting pools) about Optimus and Megatron’s private meetings.

All things considered, it hadn’t been that difficult to resist temptation, too. There was so much to be done. Messages needed to be sent out, contact to Autobot and Decepticon forces across the galaxy needed to be established, preliminary treaties needed to be drawn up – really, even with the now steady supply of energon, Optimus hardly stood much of a chance to get overcharged at all. On top of everything, he also had to do the negotiating with the humans, who were less than convinced that Megatron was being serious about this. In the end, the Autobots had removed themselves from the planet to aboard the Nemesis in the hopes that decreased visibility would also decrease fears.

It hadn’t worked quite the intended way, but it had sped up the process of reviving Cybertron. Once Optimus and Soundwave had finished deciphering the Iacon database and the Keys had been found – and Team Prime had suddenly found itself increased by one very disbelieving, suspicious member –, the Omega Lock, to the almost-disbelief of many of the troops, had worked its magic. And then, well, Megatron had simply taken the Nemesis back to Cybertron and Team Prime had maintained contact to Earth via long-distance calls and spacebridges. Of course the humans were still suspicious (and rather frightened of a hostile take-over), but it had been human years now since the last bot officially left Earth, and things appeared to be calming down.

Optimus did feel a bit bad for paying Earth an unannounced visit like this, but in the end, as the Autobot commander, he was still considered a diplomatic entity and therefore entitled to be on Earth. A status Megatron had not been granted, which rendered his current presence here rather a delicate subject – but it wasn’t exactly like he had spacebridged into the middle of Manhattan. There were no humans around, Optimus had scouted the area thoroughly earlier. And he had only been following Optimus, so he wasn’t going to point out to Megatron that this could result in diplomatic complications if anyone found out.

Besides, they had a much more important topic to discuss. Megatron ex-vented deeply when Optimus said nothing more and almost mumbled, “We will become conjunx endurae in a few groons. We could wait until after the ceremony.”

“We could,” Optimus agreed, uncomfortable. It was rare to wait with interfacing until after the ceremony, but not unheard of. The main reason he and Megatron had been waiting for the right time was that they had first had to re-establish a trusting relationship which would allow them to engage interfacing protocols in each other’s presence without having to manually shut off battle protocols every second klik. After all, there was a reason why these protocols could not be activated if the bots in question had their battle protocols running at the same time, and why every medic strongly advised against using the manual override. There was just too much of a risk that the interference would cause a malfunction and the charge from the interface mod be released back into the normal circuits, which in turn was likely to fry not only the bot who was malfunctioning, but also the one touching and, thereby, grounding them.

The trust had been re-established some time ago already, the problem had been of a different nature, because if Optimus was entirely truthful, they had just been too busy lately to make the time for an extended interface session. As little as they wanted their first experience together to be tainted by old suspicions and fears, Optimus had no wish either to simply rush through it because he or Megatron needed an overload. With all their history, he wanted to be able to enjoy it to its fullest extent, with the leisure to do so instead of having to hurry to the next meeting. Take the time to get to know Megatron thoroughly in this area as well.

Megatron ex-vented again and shifted a little, clearly bracing himself for something. “Well? Do you want to wait?”

Optimus shifted, too. “Do you?”

“I asked first.”

Optimus covered his laugh at the petulant tone with a cough and felt less uncomfortable. “My misgivings about interfacing with you lately related to the timespan we would have at our disposition.”

Megatron made a rude sound and rolled his optics. “Your ‘misgivings’, huh? Well, _my_ ‘misgivings’ relate to your lack of interest. And much as I dislike it, Soundwave is right about one thing: It will certainly look bad if I never approach my conjunx for an overload and seek release with others or alone. So we had better talk about it before the ceremony, so we know what to say if we’re asked.”

Oh. Optimus hadn’t thought about that. Yes, of course. It would look bad if he and Megatron never engaged in interface with each other. Becoming conjunx endurae was all well and good, but still not interfacing would lend suspicions of lingering distrust between them credence.

“I disliked the thought of not having enough time to pay proper attention to you. I did not want to do you the disservice of leaving you alone in berth right after we were done,” he said honestly and Megatron looked rather mollified at that, tension disappearing.

“Did you?” he almost-purred. “We could have made time, you know.”

“With all the work there was to do?” Optimus protested and Megatron shook his helm at him.

“I will have to teach you yet to be more selfish, Optimus Prime. Has your medic not told you that it isn’t healthy to ignore your overcharge for too long?”

Optimus smiled at the exasperation hidden in the words and the way Megatron was now bantering with him easily. “I haven’t been overcharged, Megatron.”

“Jazz?” Megatron guessed, then grimaced. “Please don’t tell me you’ve been berthing that little yellow menace!”

Optimus couldn’t help but chuckle. “No, not Jazz, not Ratchet either and certainly not Bumblebee.”

Megatron looked confused. “I didn’t think those two wreckers would let someone else join in. Oh, pit, Ultra Magnus?”

Optimus almost laughed out loud at the horrified tone. “Primus, Megatron, no! I don’t think Ultra Magnus would, even if I asked! Have you already forgotten your own courting gift to me?”

Oh, that had been the right thing to say. Megatron brightened on infrared and poofed out his plating in unmistakable pride. “Well, in that case, I guess I can overlook your rebuttals of my offers,” he rumbled, almost preening.

“I have not -” Optimus stopped, then cleared his intake. He _had_ turned Megatron down a few times. He just hadn’t thought that he would take that as a sign of lacking interest. “I did not mean to imply I had lost interest completely.”

Megatron huffed, amused. “I think I’ll have to agree with Soundwave on you having a particularly bad servo regarding anything courtship-related. If half of our meetings hadn’t been about our bonding ceremony, I would have thought you were reconsidering conjunxing.”

The reminder of his first, failed courtship of Megatronus had Optimus’ core temperature jumping. He brought a servo up and covered his optics. “I did not mean to leave it in your berth!”

Megatron laughed and shifted closer. “You mentioned that. A few times. However, now that we have established that your unusual hesitance in approaching your future conjunx for release did not originate in a dislike of said conjunx, and seeing as our ceremony is approaching fast, what are your views on an overload or two?”

Optimus cleared his intake. “I would be – very amenable?”

Megatron laughed again, a deep, rumbling sound that had Optimus’ spark spinning faster. “In your choice of words, at least, you are still all Orion Pax.” His voice softened as he stared into Optimus’ optics, but he did not continue speaking. Instead, he reached out and gently pulled Optimus into a kiss that was eagerly reciprocated. There was quite a bit of charge in Optimus’ interface mod, not yet uncomfortable, but enough that an overload now would help him deal with the stress-induced excess current he anticipated creating tomorrow during the ceremony. Megatron’s proximity and the anticipation were doing their part in creating excess current even now, and Optimus put his servos on Megatron’s plating and began tracing transformation seams. Indeed, if he thought about it, he could hardly come up with a better time and place for their first interface: On a blanket given during their courting (however little Optimus had been aware that it had been a courting gift), on the planet that had seen the first rotations of their peace, underneath the stars. Megatron’s kisses were passionate and his servos demanding, and before Optimus could react, Megatron had overbalanced them and sat down on top of Optimus, grinning with satisfaction.

“Ah, Optimus, of all the things to come out of this peace treaty, seeing you underneath me is the best,” he purred and Optimus chuckled, then gasped as Megatron rubbed his interface panel against his stomach plating, the heat unmistakable.

“Oh? Am I to understand then that you will be doing all the work?”

Megatron rumbled, leaning forward and kissing Optimus once more, servos lazily trailing down his sides. “Will I have to? Or is there a chance that you can be convinced to spike me every now and then as well?”

Instead of answering, Optimus executed a grapple manoeuvre and flipped them both over, holding Megatron’s wrists above his helm for good measure as he slid his frame along the sturdier one in a sensuous move and listened to Megatron’s vents hitch. “I think I will enjoy either mode, although I have yet to make the acquaintance of the real deal.”

Megatron shuddered, optics bright, smirking. “Tell me, Optimus, how well did my gift fit your valve? Did you imagine me over you when you made use of it? Like this?”

His hold was broken and they crashed onto their sides, Megatron quickly taking control of him again. Instead of triggering his battle protocols, Optimus felt heat rush along his leads and his mod twitch with the influx of more charge. Then it pinged him, quite urgently, and he rubbed his pelvis against Megatron. “I did. Would you like a demonstration?”

The optics blazed and Megatron sputtered static for a moment. “Do you have it with you?”

Optimus narrowed his optics and lowered his voice as deep as he could go. “In my subspace. Or would you prefer to test my valve capacity yourself?”

Megatron stared down at him, obviously torn. Optimus permitted himself a little wicked smile. “Or should I extrapolate from your choice of gift that you prefer using your valve as well?”

“I -” Megatron reset his vocaliser several times before he could speak almost without static. “I might make use of it more often.”

“Oh?” The grip on him was loosening. Optimus surreptitiously pulled up his legs to get ready to buck Megatron off. “Did you imagine me using the replica you gave me when you were alone in your berth with your digits in your own valve?”

Megatron choked and Optimus struck, flipping them back over with a crash and clanging of armour. He did not care. There was no-one around, after all. “What would you have had me do, had I been there?”

“Eat me out,” Megatron groaned, glyphs layered with _lust, desire, longing._ “Put your glossa inside me and make me scream. And then let me push that replica inside you and make _you_ scream.”

Optimus’ vents almost stopped. “I think that can be arranged.”

Megatron willingly opened his legs when he pushed them apart and settled down between them, coming face-to-face with Megatron’s interface array for the first time. It was beautiful. The modesty panel was already retracted, but the valve was still in the process of extending itself into Megatron’s belly, and Optimus darted forward quickly and pressed a kiss to a few connector clusters before they extended out of easy reach.

Megatron yelped. Optimus chuckled, then traced the connector-rich entrance with a careful digit and followed it up with an indulgent lick. Megatron moaned. “Optimus …”

His own interface mod was buzzing with charge, and given that Megatron had just delivered pretty explicit instructions on what he would like them to be doing, Optimus let his own valve unfold with no small amount of relief, moaning into Megatron’s valve. This was going to be perfect. His mouth on Megatron, a replica of Megatron’s spike inside him, Primus, he might just overload from the simple prospect.

Apparently, he wasn’t the only one, because Megatron’s moans rose in volume, music to Optimus’ audials, until he gasped out, “Unicron take you, where the pit did you learn that?”

Optimus removed his glossa, and since he was passing by anyway, applied the twirl-twist motion of his glossa that Megatron was most likely referring to to the connector cluster similar to the one his own interface mod sported. Then he looked up. “I used to be a spike-mech, you know. I have a bit of practice with valves not my own.”

Megatron was looking down his frame at him, optics blown wide and almost crimson. “I always suspected Orion Pax was. Don’t stop!”

Optimus chuckled and obediently went back when Megatron’s servo pushed him back down. Satisfyingly, when he pushed his glossa back inside, Megatron’s legs jerked and another loud moan reached his audials. Lubricant gushed down and dripped onto the blanket beneath them, and for a moment Optimus was distracted by the thought that he had tried so hard to keep it clean – and then he just felt gratitude at how things had worked out, at the role this blanket had played in paving the way to where they were now. And twirled his glossa against a connector cluster halfway up Megatron’s valve, feeling the charge ground itself in his glossa.

“Stop!” Megatron gasped out from above. “Spike replica! Get it out, now!”

Optimus backed up, fumbling blindly in his subspace to retrieve the toy. Megatron practically ripped it from his servos, turning it on immediately. “Lie down. Do I need to prepare you?”

“No. No, it will be fine, it’s just the right size …” Optimus followed the tugging until his helm was comfortably bedded on Megatron’s leg, the dripping valve right in front of him, Megatron’s other leg across his shoulder, his own exposed valve close enough to Megatron to feel the hot vents on the metalmesh. Megatron groaned in appreciation, darting forward and stealing a quick taste before he pressed the vibrating toy against his entrance and Optimus arched, moaning and keeping himself from trashing with difficulty, then started begging. “Yes, like that, deeper, Megatron, please, deeper -”

The toy hit the innermost connector cluster and then Megatron hit the second button and the circuits closed, current pressed from the toy into his valve connectors, oh Primus, he could not -

Desperate, Optimus buried his face back in Megatron’s valve and started thrusting his glossa inside as fast as he could. He could barely hear Megatron’s moans over the crackle of charge, but he could feel Megatron twisting and turning the toy, moving it in and out, and he could feel Megatron’s valve clamping down on his glossa and the plasma arcs crackling across his plating as he shuddered against Optimus in overload.

He promptly followed suit, moaning so loudly he was pretty sure even the inhabitants of Jasper miles away had heard it, then slumped against Megatron’s bulk in sated satisfaction. Distantly, he felt Megatron fumble with the toy, turn it off, slide it out, and he hummed a happy note. A servo started petting his leg, his side, what parts of his frame Megatron could reach from where he lay until he finally spoke. “Turn around?”

Sluggishly, Optimus obeyed, crawling out from between Megatron’s legs and moving up and around until he lay beside Megatron, able to gaze at the red optics and the almost peaceful expression on the scarred face. Megatron tipped his helm forward and rested it against Optimus’.

“Orion,” he whispered and Optimus’ spark lurched. He and Megatron had talked about that – how Orion Pax became Optimus Prime, how a little archivist regained memories his spark had always carried inside, memories of being the thirteenth Prime, how he adapted to the Matrix, his new frame, incorporated the memories of his prior functioning and hid the memories of the second away in his memory banks to protect them – and yet Optimus had always felt that Megatron could not quite believe that he really was Orion Pax and Optimus Prime both.

“Yes?” he replied and the red optics unshuttered and looked at him.

“Do you know how long I have carried this blanket with me?” Megatron asked, his voice hushed and slightly strangled. Optimus shook his helm and Megatron’s field rippled with pain, causing Optimus to pull him closer yet. “I bought it three deca-cycles after you gave me the datapad. The second one.” A deep vent. “Openly presented, no more than a token of friendship, when I had been hoping you -” Another deep vent. Optimus could not speak, he simply pressed close. ”No matter. I did not even know how I would sneak it into your quarters given that I was not allowed to travel to Iacon, yet -”

Somewhere in his processor, Optimus had suspected something along those lines. Even back when he had found the blanket, he had marvelled at the fact that such an item could have survived the war. To hear it spoken out loud though stole the air from his vents and made his spark expand in its chamber.

“Megatron, would you -” He broke off, collected himself, then continued. “In a few groons, we will be conjunxed.”

A slight nod. Optimus steeled himself. “Back when I asked you about the gladiator customs of courting, you told me gladiators did not conjunx each other. They sparkbonded.”

Megatron stilled in his arms, his expression turning blank. “Yes.”

Optimus cycled another vent, urging himself on. “You never spoke of it, although you courted me after the fashion of the gladiators.”

Megatron shrugged, a motion meant to appear careless and dismissive, but Optimus knew him, and knew him well. “Conjunx endurae are recognised by the law. Sparkmates aren’t.”

Optimus hummed. “Yet it is your custom. It is what the Decepticons will recognise as the proper way to go about things.”

Megatron’s optics blazed for a moment. “None of them questions the legitimacy of your place by my side, sparkbonded or not. I made my promises to you when I presented my gifts. They are as binding as any vow we will speak during the ceremony.”

“I know.” Optimus took a last deep vent. “Megatron of Kaon, Lord of the Decepticons, would you do me the honour of becoming my sparkmate?”

He was sure Megatron had seen it coming, there was no way he hadn’t caught on to what Optimus was driving at. And he still opened and closed his mouth a few times without managing to speak. Optimus almost felt dizzy with joy, anticipation, a sliver of fear, but mostly overwhelming, deep need to remain by Megatron’s side for as long as he functioned.

Finally, Megatron cleared his intake and grumbled, “Ultra Magnus’ll have our helms for those last-klik changes!”

Optimus could not help it; he snorted a laugh. “He will survive. And no-one says we have to work it into the ceremony.” He pressed a kiss to Megatron’s mouth. “We can do it tomorrow after the ceremony. In our quarters, once we’re alone.”

Megatron hesitated, then heaved a put-upon ex-vent. “You always make things so complicated, Orion Pax! We are already going to be conjunxed. It doesn’t get more official than that.”

Optimus smiled, stroking a servo over Megatron’s back. “Is that a yes?”

Megatron cleared his intake again. “Orion Pax of Iacon, also known as Optimus Prime of Cybertron. Yes. It is.”


End file.
